diff --git a/CHANGELOG.md b/CHANGELOG.md
index 280f90907..1484945a5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 - Use union type instead of enum for SettingName
 - Fix a bug: wrong variable reference in `SingleSignOnConcern:Merge_form_sso`
 - Fix a bug: wrong focus behavior on text editor
+- Fix a bug: trainings monitoring is not available
 
 ## v5.4.15 2022 August 1
 
diff --git a/app/controllers/api/trainings_controller.rb b/app/controllers/api/trainings_controller.rb
index b8902da78..83240a232 100644
--- a/app/controllers/api/trainings_controller.rb
+++ b/app/controllers/api/trainings_controller.rb
@@ -52,7 +52,13 @@ class API::TrainingsController < API::ApiController
     authorize Training
     @training = Training.find(params[:id])
     @availabilities = @training.availabilities
-                               .includes(slots: { slots_reservations: { reservations: { statistic_profile: [:trainings, user: [:profile]] } } })
+                               .includes(slots: {
+                                           slots_reservations: {
+                                             reservation: {
+                                               statistic_profile: [:trainings, { user: [:profile] }]
+                                             }
+                                           }
+                                         })
                                .where('slots_reservations.canceled_at': nil)
                                .order('availabilities.start_at DESC')
   end
diff --git a/app/views/api/trainings/availabilities.json.jbuilder b/app/views/api/trainings/availabilities.json.jbuilder
index b3701a28e..e4163caa1 100644
--- a/app/views/api/trainings/availabilities.json.jbuilder
+++ b/app/views/api/trainings/availabilities.json.jbuilder
@@ -1,11 +1,13 @@
+# frozen_string_literal: true
+
 json.extract! @training, :id, :name, :description, :machine_ids, :nb_total_places, :public_page
 json.availabilities @availabilities do |a|
   json.id a.id
   json.start_at a.start_at.iso8601
   json.end_at a.end_at.iso8601
-  json.reservation_users a.slots.map do |slot|
-    json.id slot.reservations.first.statistic_profile.user_id
-    json.full_name slot.reservations.first.statistic_profile&.user&.profile&.full_name
-    json.is_valid slot.reservations.first.statistic_profile.trainings.include?(@training)
+  json.reservation_users a.slots.map(&:slots_reservations).flatten.map do |sr|
+    json.id sr.reservation.statistic_profile.user_id
+    json.full_name sr.reservation.statistic_profile.user&.profile&.full_name
+    json.is_valid sr.reservation.statistic_profile.trainings&.include?(@training)
   end
 end
diff --git a/test/integration/trainings/availabilities_test.rb b/test/integration/trainings/availabilities_test.rb
new file mode 100644
index 000000000..6e0c31450
--- /dev/null
+++ b/test/integration/trainings/availabilities_test.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+module Trainings; end
+
+class Trainings::AvailabilitiesTest < ActionDispatch::IntegrationTest
+  def setup
+    @admin = User.find_by(username: 'admin')
+    login_as(@admin, scope: :user)
+  end
+
+  test 'get trainings availabilities list' do
+    training = Training.find(1)
+    get "/api/trainings/#{training.id}/availabilities"
+
+    # Check response format & status
+    assert_equal 200, response.status, response.body
+    assert_equal Mime[:json], response.content_type
+
+    # Check the correct training was returned
+    result = json_response(response.body)
+    assert_equal training.id, result[:id], 'training id does not match'
+    assert_not_empty result[:availabilities], 'no training availabilities were returned'
+  end
+end